/* SPDX-License-Identifier: GPL-2.0 */
/*
* PowerPC ELF notes.
*
* Copyright 2019, IBM Corporation
*/
#include <linux/elfnote.h>
#include <asm/elfnote.h>
/*
* Ultravisor-capable bit (PowerNV only).
*
* Bit 0 indicates that the powerpc kernel binary knows how to run in an
* ultravisor-enabled system.
*
* In an ultravisor-enabled system, some machine resources are now controlled
* by the ultravisor. If the kernel is not ultravisor-capable, but it ends up
* being run on a machine with ultravisor, the kernel will probably crash
* trying to access ultravisor resources. For instance, it may crash in early
* boot trying to set the partition table entry 0.
*
* In an ultravisor-enabled system, a bootloader could warn the user or prevent
* the kernel from being run if the PowerPC ultravisor capability doesn't exist
* or the Ultravisor-capable bit is not set.
*/
#ifdef CONFIG_PPC_POWERNV
#define PPCCAP_ULTRAVISOR_BIT (1 << 0)
#else
#define PPCCAP_ULTRAVISOR_BIT 0
#endif
/*
* Add the PowerPC Capabilities in the binary ELF note. It is a bitmap that
* can be used to advertise kernel capabilities to userland.
*/
#define PPC_CAPABILITIES_BITMAP (PPCCAP_ULTRAVISOR_BIT)
ELFNOTE(PowerPC, PPC_ELFNOTE_CAPABILITIES,
.long PPC_CAPABILITIES_BITMAP)
